The atomic_spin_nop() macro can be used to run arch-specific
code in the body of a spin loop to potentially improve efficiency.
RISC-V's Zihintpause extension includes a PAUSE instruction for
this use-case, which is encoded as a HINT, which means that it
behaves like a NOP on systems that don't implement Zihintpause.
Binutils supports Zihintpause since 2.36, so this patch uses
the ".insn" directive to keep the code compatible with older
toolchains.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
MIPSr6 has MADDF.s/MADDF.d instructions, which are fused.
In MIPS ISA, double support can be subsetted. Only FMAF is enabled
for this case.
* sysdeps/mips/fpu/math-use-builtins-fma.h
Signed-off-by: YunQiang Su <syq@gcc.gnu.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
The upcoming parisc (hppa) v6.11 Linux kernel will include vDSO
support for gettimeofday(), clock_gettime() and clock_gettime64()
syscalls for 32- and 64-bit userspace.
The patch below adds the necessary glue code for glibc.
Signed-off-by: Helge Deller <deller@gmx.de>
Changes in v2:
- add vsyscalls for 64-bit too
The walk benchmarks don't measure anything useful - memory is not initialized
properly so doing a single walk in 32MB just measures reading the 4KB zero
page for reads and clear_page overhead for writes. The memset variants don't
even manage to do a walk in the 32MB region due to using incorrect pointer
increments... Neither is it clear why it is walking backwards since this
won't confuse modern prefetchers. If you fix the benchmark and print the
bandwidth, the results are identical for all sizes larger than ~1KB since it
is just testing memory bandwidth of a single 32MB block. This case is already
tested by the large benchmark, so overall it doesn't seem useful to keep these.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The previous version expanded $0 and $@ twice.
The new version defines a q no-op shell command. The Perl syntax
error is masked by the eval Perl function. The q { … } construct
is executed by the shell without errors because the q shell function
was defined, but treated as a non-expanding quoted string by Perl,
effectively hiding its context from the Perl interpreter. As before
the script is read by require instead of executed directly, to avoid
infinite recursion because the #! line contains /bin/sh.
Introduce the “fatal” function to produce diagnostics that are not
suppressed by “do”. Use “do” instead of “require” because it has
fewer requirements on the executed script than “require”.
Prefix relative paths with './' because “do” (and “require“ before)
searches for the script in @INC if the path is relative and does not
start with './'. Use $_ to make the trampoline shorter.
Add an Emacs mode marker to indentify the script as a Perl script.
The test is not a run-time check, so update the description.
Also use readelf -W for a more stable output format and fix
an LC_ALL typo.
This avoids garbled configure messages:
checking for s390-specific static PIE requirements (runtime check)... 0x0000000000000017 (JMPREL) 0x280
yes
Based on a -march=x86-64-v4 -mfpmath=sse build, with and without
--disable-multi-arch, running on a Zen 4 CPU. Also used different
-march=x8i6-64-v… settings.
Generation of the Perl script does not depend on Perl, so we can
always install it even if $(PERL) is not set during the build.
Change the malloc/mtrace.pl text substition not to rely on $(PERL).
Instead use PATH at run time to find the Perl interpreter. The Perl
interpreter cannot execute directly a script that starts with
“#! /bin/sh”: it always executes it with /bin/sh. There is no
perl command line switch to disable this behavior. Instead, use
the Perl require function to execute the script. The additional
shift calls remove the “.” shell arguments. Perl interprets the
“.” as a string concatenation operator, making the expression
syntactically valid.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
HWCAP value is overwritten at the first comparison of the LASX case.
The second comparison at LSX get incorrect result.
Change to use t0 to save HWCAP value, and use t1 to save comparison
result.
The _dl_sysdep_parse_arguments function contains initalization
of a large on-stack variable:
dl_parse_auxv_t auxv_values = { 0, };
This uses a non-inline version of memset on powerpc64le-linux-gnu,
so it must use the baseline memset.
A desired hugetlb page size can be encoded in the flags parameter of
system calls such as mmap() and shmget(). The Linux UAPI headers have
included explicit definitions for these encodings since v4.14.
This patch adds these definitions that are used along with MAP_HUGETLB
and SHM_HUGETLB flags as specified in the corresponding man pages. This
relieves programs from having to duplicate and/or compute the encodings
manually.
Additionally, the filter on these definitions in tst-mman-consts.py is
removed, as suggested by Florian. I then ran this tests successfully,
confirming the alignment with the kernel headers.
PASS: misc/tst-mman-consts
original exit status 0
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Tested-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Remove the definitions of HWCAP_IMPORTANT after removal of
LD_HWCAP_MASK / tunable glibc.cpu.hwcap_mask. There HWCAP_IMPORTANT
was used as default value.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the environment variable LD_HWCAP_MASK and the tunable
glibc.cpu.hwcap_mask as those are not used anymore in common-code
after removal in elf/dl-cache.c:search_cache().
The only remaining user is sparc32 where it is used in
elf_machine_matches_host(). If sparc32 does not need it anymore,
we can get rid of it at all. Otherwise we could also move
LD_HWCAP_MASK / tunable glibc.cpu.hwcap_mask to be sparc32 specific.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the definitions of _DL_PLATFORMS_COUNT as those are not used
anymore after removal in elf/dl-cache.c:search_cache().
Note: On x86, we can also get rid of the definitions
HWCAP_PLATFORMS_START and HWCAP_PLATFORMS_COUNT.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the definitions of _DL_FIRST_PLATFORM as those were only used
in the _DL_HWCAP_PLATFORM definitions and in _dl_string_platform().
Both were removed.
Note: Removed on every architecture despite of powerpc, where
_dl_string_platform() is still used.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the definitions of _DL_HWCAP_PLATFORM as those are not used
anymore after removal in elf/dl-cache.c:search_cache().
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the platform strings in dl-procinfo.c where also
the implementation of _dl_string_platform() was removed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Despite of powerpc where the returned integer is stored in tcb,
and the diagnostics output, there is no user anymore.
Thus this patch removes the diagnostics output and
_dl_string_platform for all other platforms.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The legacy hwcaps mechanism was removed with glibc 2.37:
See this commit series:
- d178c67535
x86_64: Remove platform directory library loading test
- 6099908fb8
elf: Remove legacy hwcaps support from the dynamic loader
- b78ff5a25d
elf: Remove legacy hwcaps support from ldconfig
- 4a7094119c
elf: Remove hwcap parameter from add_to_cache signature
- cfbf883db3
elf: Remove hwcap and bits_hwcap fields from struct cache_entry
- 78d9a1620b
Add NEWS entry for legacy hwcaps removal
- ab40f20364
elf: Remove _dl_string_hwcap
- e76369ed63
elf: Simplify output of hwcap subdirectories in ld.so help
According to Florian Weimer, this was an oversight and should also
have been removed.
As ldconfig does not generate ld.so.cache entries with hwcap/platform
bits in the hwcap-field anymore, this patch now skips those entries.
Thus currently only named-hwcap-entries and the default entries are
allowed.
For named-hwcap entries bit 62 is set and also the isa-level bits can
be set.
For the default entries the hwcap-field is 0.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Both defines are not used anymore. Those were only used for
_dl_string_hwcap(), which itself was removed with commit
ab40f20364
"elf: Remove _dl_string_hwcap"
Just clean up.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
As discussed at the patch review meeting
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Simon Chopin <simon.chopin@canonical.com>
C23 adds various <math.h> function families originally defined in TS
18661-4. Add the exp2m1 and exp10m1 functions (exp2(x)-1 and
exp10(x)-1, like expm1).
As with other such functions, these use type-generic templates that
could be replaced with faster and more accurate type-specific
implementations in future. Test inputs are copied from those for
expm1, plus some additions close to the overflow threshold (copied
from exp2 and exp10) and also some near the underflow threshold.
exp2m1 has the unusual property of having an input (M_MAX_EXP) where
whether the function overflows (under IEEE semantics) depends on the
rounding mode. Although these could reasonably be XFAILed in the
testsuite (as we do in some cases for arguments very close to a
function's overflow threshold when an error of a few ulps in the
implementation can result in the implementation not agreeing with an
ideal one on whether overflow takes place - the testsuite isn't smart
enough to handle this automatically), since these functions aren't
required to be correctly rounding, I made the implementation check for
and handle this case specially.
The Makefile ordering expected by lint-makefiles for the new functions
is a bit peculiar, but I implemented it in this patch so that the test
passes; I don't know why log2 also needed moving in one Makefile
variable setting when it didn't in my previous patches, but the
failure showed a different place was expected for that function as
well.
The powerpc64le IFUNC setup seems not to be as self-contained as one
might hope; it shouldn't be necessary to add IFUNCs for new functions
such as these simply to get them building, but without setting up
IFUNCs for the new functions, there were undefined references to
__GI___expm1f128 (that IFUNC machinery results in no such function
being defined, but doesn't stop include/math.h from doing the
redirection resulting in the exp2m1f128 and exp10m1f128
implementations expecting to call it).
Tested for x86_64 and x86, and with build-many-glibcs.py.
C23 adds various <math.h> function families originally defined in TS
18661-4. Add the log10p1 functions (log10(1+x): like log1p, but for
base-10 logarithms).
This is directly analogous to the log2p1 implementation (except that
whereas log2p1 has a smaller underflow range than log1p, log10p1 has a
larger underflow range). The test inputs are copied from those for
log1p and log2p1, plus a few more inputs in that wider underflow
range.
Tested for x86_64 and x86, and with build-many-glibcs.py.
C23 adds various <math.h> function families originally defined in TS
18661-4. Add the logp1 functions (aliases for log1p functions - the
name is intended to be more consistent with the new log2p1 and
log10p1, where clearly it would have been very confusing to name those
functions log21p and log101p). As aliases rather than new functions,
the content of this patch is somewhat different from those actually
adding new functions.
Tests are shared with log1p, so this patch *does* mechanically update
all affected libm-test-ulps files to expect the same errors for both
functions.
The vector versions of log1p on aarch64 and x86_64 are *not* updated
to have logp1 aliases (and thus there are no corresponding header,
tests, abilist or ulps changes for vector functions either). It would
be reasonable for such vector aliases and corresponding changes to
other files to be made separately. For now, the log1p tests instead
avoid testing logp1 in the vector case (a Makefile change is needed to
avoid problems with grep, used in generating the .c files for vector
function tests, matching more than one ALL_RM_TEST line in a file
testing multiple functions with the same inputs, when it assumes that
the .inc file only has a single such line).
Tested for x86_64 and x86, and with build-many-glibcs.py.
POSIX.1-2024 (now official) specifies tm_gmtoff and tm_zone.
This is a good time to update the manual’s “Date and Time”
chapter so I went through it, fixed some outdated
stuff that had been in there for decades, and improved it to match
POSIX.1-2024 better and to clarify some implementation-defined
behavior. Glibc already conforms to POSIX.1-2024 in these matters, so
this is merely a documentation change.
* manual/examples/strftim.c: Use snprintf instead of now-deprecated
function asctime. Check for localtime failure. Simplify by using
puts instead of fputs. Prefer ‘buf, sizeof buf’ to less-obvious
‘buffer, SIZE’.
* manual/examples/timespec_subtract.c: Modernize to use struct
timespec not struct timeval, and rename from timeval_subtract.c.
All uses changed. Check for overflow. Do not check for negative
return value, which ought to be OK since negative time_t is OK.
Use GNU indenting style.
* manual/time.texi:
Document CLOCKS_PER_SEC, TIME_UTC, timespec_get, timespec_getres,
strftime_l.
Document the storage lifetime of tm_zone and of tzname.
Caution against use of tzname, timezone and daylight, saying that
these variables have unspecified values when TZ is geographic.
This is what glibc actually does (contrary to what the manual said
before this patch), and POSIX is planned to say the same thing
<https://austingroupbugs.net/view.php?id=1816>.
Also say that directly accessing the variables is not thread-safe.
Say that localtime_r and ctime_r don’t necessarily set time zone
state. Similarly, in the tzset documentation, say that it is called
by ctime, localtime, mktime, strftime, not that it is called by all
time conversion functions that depend on the time zone.
Say that tm_isdst is useful mostly just for mktime, and that
other uses should prefer tm_gmtoff and tm_zone instead.
Do not say that strftime ignores tm_gmtoff and tm_zone, because
it doesn’t do that.
Document what gmtime does to tm_gmtoff and tm_zone.
Say that the asctime, asctime_r, ctime, and ctime_r are now deprecated
and/or obsolescent, and that behavior is undefined if the year is <
1000 or > 9999. Document strftime before these now-obsolescent
functions, so that readers see the useful function first.
Coin the terms “geographical format” and “proleptic format” for the
two main formats of TZ settings, to simplify exposition. Use this
wording consistently.
Update top-level proleptic syntax to match POSIX.1-2024, which glibc
already implements. Document the angle-bracket quoted forms of time
zone abbreviations in proleptic TZ. Say that time zone abbreviations
can contain only ASCII alphanumerics, ‘+’, and ‘-’.
Document what happens if the proleptic form specifies a DST
abbreviation and offset but omits the rules. POSIX says this is
implementation-defined so we need to document it. Although this
documentation mentions ‘posixrules’ tersely, we need to rethink
‘posixrules’ since I think it stops working after 2038.
Clarify wording about TZ settings beginning with ‘;’.
Say that timegm is in ISO C (as of C23).
Say that POSIX.1-2024 removed gettimeofday.
Say that tm_gmtoff and tm_zone are extensions to ISO C, which is
clearer than saying they are invisible in a struct ISO C enviroment,
and gives us more wiggle room if we want to make them visible in
strict ISO C, something that ISO C allows.
Drop mention of old standards like POSIX.1c and POSIX.2-1992 in the
text when the history is so old that it’s no longer useful in a
general-purpose manual.
Define Coordinated Universal Time (UTC), time zone, time zone ruleset,
and POSIX Epoch, and use these phrases more consistently.
Improve TZ examples to show more variety, and to reflect current
practice and timestamps. Remove obsolete example about Argentina.
Add an example for Ireland.
Don’t rely on GCC extensions when explaining ctime_r.
Do not say that difftime produces the mathematically correct result,
since it might be inexact.
For clock_t don’t say “as in the example above” when there is no
such example, and don’t say that casting to double works “properly
and consistently no matter what”, as it suffers from rounding and
overflow.
Don’t say broken-down time is not useful for calculations; it’s
merely painful.
Say that UTC is not defined before 1960.
Rename Time Zone Functions to Time Zone State. All uses changed.
Update Internet RFC 822 → 5322, 1305 → 5905. Drop specific years of
ISO 8601 as they don’t matter.
Minor style changes: @code{"..."} → @t{"..."} to avoid overquoting in
info files, @code → @env for environment variables, Daylight Saving
Time → daylight saving time, white space → whitespace, prime meridian
→ Prime Meridian.
